A memory management system includes a first virtual machine, a second virtual machine, and a hypervisor configured to manage a region to which the first virtual machine and the second virtual machine access in a memory, control the first virtual machine to access a first region and a shared region in the memory, control the second virtual machine to access the shared region and a second region different from the first region in the memory, and in response to a request of the first virtual machine, store an in-memory data isolation (IMDI) table that indicates an IMDI region that a task of the first virtual machine accesses and a task of the second virtual machine does not access, in the memory.